Wednesday, August 29, 2012

Valve adjustments on your Acura 101

Some Valve Adjustment Wisdom from Acura of Pleasanton

Performing regular maintence is important for longivity and to keep your Acura performing its best, however if the decision were to chose to perform only a few maintenance items for your Acura, one in particular should not be ignored and that would be a valve adjustment.

Most car owners know about regular maintenance such as oil and filter changes, engine air filter replacement, tire rotation, and to check for brake wear. While the basics of the internal combustion automotive engine has not changed much over the past 100 years, for most owners, the internal workings of a car's engine is still a mysterious place. 

Its here where all the magic happens, the pistons move up and down pulling in air/fuel, ignited by a sparkplug, pushing the piston back down, the spent fuel mixture is expelled through the exhaust while spinning the crankshaft through a transmission to create motion.

This task of creating motion can occurs upwards of 1,500 times a minute or more. All metal to metal surfaces are only separated by a microscopic film of oil and over time wear still occurs. While most internal components of a modern automobile engine only require routine lubricating fluid replacement, a periodic mechanical valve adjustment is a critical maintenance function that may end up with costly internal engine repairs if not addressed.

What a typical mechanical valve adjuster looks like

Over time, the valve faces and seats wear causing the gap, sometimes smaller than a quarter of a millimeter, at the valve tip to get closer to the rocker arm or camshaft. Eventually the valve will run out of the required clearance and the valve may be held slightly open all the time. When the valve is not able to seat fully is when a couple of problems can occur.

The heat that the valve absorbs during the combustion process may not dissipate normally and can overheat or burn the valve and/or valve seat leading to costly mechanical repairs.

Valve clearances can be less than quarter of a millimeter
 
In addition, if the valves do not seat properly, the vehicle's computer will sense a change in the air pressure in the fuel induction system and may send signals to give the engine more fuel because it thinks the gas pedal is opened more than it actually is. Not only does this waste expensive fuel but could also damage the catalytic converter as it works overtime trying to burn off the excess fuel.

Unfortunately, more and more manufacturers are extending the valve adjustment recommendations on the maintenance schedules or simply replacing the recommendation with a "adjust if noisy" statement. The problem with this recommendation? It is excessive valve clearance that causes noise not valves that are too tight.

For more advice on whether or not your Acura or Honda may be due to have its valve clearances inspected and adjusted, give us a call or see your Acura Service Consultant.